But even if technicians did suppress the audio, they were under no obligation to do otherwise – other than a possible moral responsibility – since despite their role in the referral system effectively making them participants in the Test match, the ICC has no regulatory framework governing their conduct.

An ICC spokesman said: "Unfortunately we don't have any code of conduct in place for broadcasters. But we continue to make improvements and to update what is required from the ­referral system.

"After every series we discuss what has happened and how we can improve. If a broadcasters' code of conduct is agreed in principle it will be referred to the cricket committee, then to the chief executive's committee and then to the ICC board for a final sign off."

Players and officials are bound by the terms of a 29-page code of conduct that covers a number of offences, several of which carry life bans from all forms of cricket.